While researching scents, I came across the topic of terpenes, which are components of scents. Terpenes are compounds of carbon and hydrogen, and are volatile substances produced by plants, fungi, insects, etc., and it seems that forest scents, floral scents, citrus scents, and menthol belong to the terpene class.Terpenes emitted by plants include isoprene (C5H8) and monoterpene (C10H16). Broadleaf trees such as Quercus serrata and Quercus mizunara, and bamboos such as Moso bamboo and Madake bamboo emit isoprene, while most coniferous trees, including larch and red pine, emit monoterpenes.
https://progearthplanetsci.org/highlights_j/617.html
Phytoncides, which we often hear about in discussions of forest bathing, are also volatile substances such as terpenes. In addition to their calming effects, they also have the effect of suppressing insects and bacteria, and forest plants apparently release phytoncides into the atmosphere from their trunks and leaves to sustain their own life and growth. I imagine that forest bathing is soothing by being exposed to terpenes.
https://www.forest.rd.pref.gifu.lg.jp/rd/rinsan/9811gr.html
Terpenes also seem to be related to the amount of clouds that form. Sand, salt, soot, smoke, and dust attract water and ice particles to form cloud nuclei, and steam and gases released by living things also form cloud nuclei. Not only are isoprene and monoterpenes the nuclei of clouds, but sesquiterpenes (C15H24) double the amount of clouds at 1/50th the amount of other volatile substances. So terpenes also affect the weather.
https://wired.jp/article/a-revelation-about-trees-is-messing-with-climate-calculations
Insects seem to communicate through smell, and the substances that give off this smell also seem to belong to the terpene family. The pheromones that insects use to communicate with each other are also similar in composition to terpines. Substances that affect different species, rather than the same species, are called allelochemicals. Terpenes seem to be able to reach distant places, so they may be used by many organisms.
https://www.sri.com/ja/press/story/
Large molecules are called terpenoids, and cholesterol, carotenoids, steroids, vitamins A, D, E, K, coenzyme Q, chlorophyll, and heme also belong to the terpenes family. Terpenes are important substances in our daily lives. Terpenes are amazing. The substances of the earth are amazing.
